Calculators have rapidly evolved from relatively simple systems providing the basic four functions of addition, subtraction, multiplication and division into complex systems capable of providing trigonometric, logarithmic, exponential, and diverse other functions. Early calculator systems were implemented using a multiplicity of discrete integrated circuit packages. Later versions were more generally implemented in large scale integrated circuits until systems, such as disclosed in copending patent application, "Variable Function Calculator," Ser. No. 163,565, filed July 19, 1971 now abandoned and replaced by continuation application Ser. No. 420,999, filed Dec. 3, 1973, were implemented having all of the electronics on a single LSI chip. Thereafter, complexity increased and a plurality of LSI chips were utilized in systems, such as set forth in "Electronic Calculator," Ser. No. 255,856, filed May 22, 1972 now abandoned and replaced by continuation application Ser. No. 360,984, filed May 16, 1973, and its continuation-in-part, Ser. No. 360,984, filed May 16, 1973 and by continuation application Ser. No. 444,226, filed Feb. 20, 1974. Even more sophisticated systems were developed employing a plurality of large scale integrated circuit chips which efficiently allowed expanded data memory and program memory storage which allowed even the most sophisticated functions to be provided in a hand-held calculator, such as described in detail in copending patent application, "Multi-Chip Calculator System, " Ser. No. 397,060, filed Sept. 13, 1973, and U.S. Pat. No. 3,904,863, both assigned to the assignee of this application.
Because of this evolution into sophisticated and complex machines, the operating instructions for these calculators have generally also become correspondingly sophisticated and complex. That is, the user of such a complex calculator generally must either frequently refer to an operating instructions guide which recites the particular sequence of inputs required by the system, or the user must recall from his own memory the particular list before the calculator can be utilized to its fullest. The typical business man, engineer and scientist who utilize these machines have neither the time to commit the variety of input operations to memory nor the time and patience to continuously refer to a guide which they would have to carry along with the calculator.
Accordingly, it is an object of the present invention to provide a self-contained data processing system having the capacity to indicate to the user thereof which input by the user is next expected by the data processing system. It is another object of the present invention to provide a calculator system having a keyboard input and an output such that the output provides an indication to the user what keyboard input is next expected by the system. Still another object of the present invention is to provide in a calculator system a keyboard input and a display output including a printer and/or a light emitting or light reflecting display in combination with an addressable memory which stores a plurality of coded prompting commands which indicate to the user the particular sequence of keyboard inputs required by the calculator system. It is yet another object of the present invention to provide the above prompting calculator system having the addressable memories wherein a permanent store memory is included for storing in binary a large number of program instructions.
Briefly and in accordance with the present invention, a prompting calculator is provided of the desk top variety having an alphanumeric printer and/or an alphanumeric display for indicating to the user thereof the next keyboard input expected by the calculator system. A permanent store program memory provides a large number of program instructions in binary form which, in combination with branching circuitry, effects data entry into the calculator and manipulation thereof or effects an output to be displayed or printed instructing the user as to the next expected input.
More specifically, a multi semiconductor chip calculator system comprises a basic pair of semiconductor chips providing conventional calculator functions, but which are implemented so as to interface with external chips providing increased data word and instruction word storage plug alphanumeric output capability. The increased instruction word storage allows a more sophisticated operating program to be utilized for implementing the prompting sequence.